• 한국정밀공학회지
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• 제21권5호
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• pp.142-148
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• 2004

In this paper, to detect exciting frequency on the latticed fence structure, fiber optic sensor using Sagnac interferometer was fabricated and tested. The latticed structure fabricated with dimension of 180 cm wide and 180 cm high, the optical fiber, 50 m in length, distributed and fixed on the latticed structure. Single mode fiber, a laser with 1,550 m wavelength, and $3{\times}3$ coupler were used. Excited vibration signal applied to the latticed structure from 200 Hz to 1 KHz. The detected optical signals were compared to the detected acceleration signals and analyzed on the time and frequency domain. Based on the experimental results, fiber optic sensor using Sagnac interferometer detected exciting frequency, effectively. This system can be applied to the structural health monitoring system.

• 대한수학회지
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• 제47권1호
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• pp.189-213
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• 2010

We study Fano manifolds of pseudoindex greater than one and dimension greater than five, which are blow-ups of smooth varieties along smooth centers of dimension equal to the pseudoindex of the manifold. We obtain a classification of the possible cones of curves of these manifolds, and we prove that there is only one such manifold without a fiber type elementary contraction.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.329.1-329
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• 2002

To detect external vibration signals on the latticed fence structure, distributed fiber optic sensor using Sagnac interferometer was fabricated and tested. The latticed structure fabricated with dimension of 170cm in width and 180cm in height, the optical fiber, 50m in lengtn, distributed and fixed on the latticed structure. It was verified the sensitivity of the Sagnac interferometer using the PZT phase modulator. Fiber-optic external vibration signal applied to the latticed structure from 100㎐ to several ㎑. (omitted)

• Composites Research
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• 제36권1호
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• pp.37-41
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• 2023

선박의 평형수처리장치 전해조 내부 용액은 해수를 전기분해 시 DSA(Dimension Stable Anode) 전극에서 생성되는 수산화물로 인하여 높은 알칼리성 분위기를 생성한다. 본 연구에서는 기존 평형수처리장치 배관에 사용되어지는 PE 코팅 강관 배관의 취약성을 대체 가능한 복합재료로써 4가지 소재를 선정하였으며, 이들 BRE(Basalt fiber reinforced epoxy), BRP(Basalt fiber reinforced unsaturated polyester), GRE(Glass fiber reinforced epoxy), GRP(Glass fiber reinforced unsaturated polyester)를 강 알칼리성 NaOH 용액에 720시간 침지 후 마찰 및 마모 시험을 통하여 재료 마찰 깊이에 따른 마찰계수와 섬유와 수지 간 계면 결합 거동을 분석하였다. 그 결과, 수지와 섬유 간의 게면 분리 현상에 대한 메커니즘을 도출하였다. 또한, 불포화폴리에스테르와 같이 상대적으로 낮은 계면 결합력의 갖는 소재의 경우, 알칼리성 용액에 침지 시간이 길어질수록 표면에서부터 시작된 열화가 내부로 급격하게 확산되어 마찰 계수의 감소로 이어지는 경향을 나타냈다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.555-560
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• 2003

Fatigue strength of concrete is ususlly presented by the Wohler Curve. But, new dimension T(time) from the view point of cyclic creep concept should be considerd. This paper presented four variable F-N-T-R relationship, this four variable relationship simultaneously accounts for the time effect and the effect of load rate. And analytical models are presented to predict fatigue strength of R/C beam strengthened with steel plate and carbon fiber sheet. Also, the correlation between the ratio of stress and the fatigue life was investigated.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2001년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 2001
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• pp.415-422
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• 2001

In this paper, the experimental study was carried out in order to compare the mechanical characteristics of multi-layer elastomeric isolation hearings where the reinforceing elements steel plates case and fiber-reinforcement case. Fiber-reinforced isolater which has the same dimension as the steel reinforced isolator had shown better efficiency in effective damping than NRB. The compression test has shown the corresponding results with the theoretical vertical stiffness in the case of flexible reinforcement. The fiber-reinforced isolator will be significantly lighter and could lead to a much less labor intensive manufacturing process.

• Journal of the Korean Wood Science and Technology
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• 제47권5호
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• pp.617-632
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• 2019

This study aimed to investigate the anatomical structure and fiber quality of four lesser-used wood species namely Benuang (O. sumatrana), Duabanga (D. moluccana), Pisang Merah (H. hellwigii), and Terap (A. odoratissimus). This study evaluated its suitability for raw material in pulp and paper manufacturing. The anatomical structure was observed macro- and microscopically. Macroscopic structures were observed directly to the wood samples, while microscopic characteristics were observed through microtome specimens. Fiber dimension was measured through macerated specimens and fiber quality was analyzed following the Rachman and Siagian's method. Results showed that these four timber species have similarity in the indistinct growth ring, diffuse porous in a radial pattern, rounded solitary vessel outline, 1 to 3 cells of ray width, deposits within the rays, fiber length, and cell wall thickness. Differences were found on vessel diameter, vessel grouping, vessel frequency, tyloses existence, type of axial parenchyma, and ray height. Based on fiber length and its derived values, the wood fibers of all species studied are suitable for pulp and paper manufacturing. They belong to the II quality class. The produced pulp and paper would have good quality, especially in tensile, folding, and tear strength. To promote their utilization, silviculture aspect of these four species has to be well understood.

• 대한치과보철학회지
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• 제50권4호
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• pp.305-310
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• 2012

수직교합고경이 감소된 환자의 보철 수복은 치과의사에게 큰 도전이다. 여러 가지 방법들을 이용해 적절한 수직교합고경을 결정하는 것이 중요하다. 85세 남자환자가 상악 우측 구치부 수복을 주소로 내원하였다. 임상 검사 결과 수직교합고경이 감소된 것으로 판단되었고, 안면 계측법, 발음 이용법, 하악 안정위 이용법, 통계적 치아 형태 이용법 등의 수직교합고경 평가 방법을 이용하여 소구치 부위에서 4 mm 증가하기로 결정하였다. 진단 왁스업을 시행하여 가역적인 overlay 형식의 임시 보철물을 상, 하악에 장착한 뒤 임상적으로 심미, 발음, 수직교합고경 기준에 따라 평가하였다. 8주 후 마모가 심한 치아에 근관 치료를 진행 한 뒤 fiber post & core를 접착하였고, 치아를 삭제하여 비가역적인 고정성, 가철성 임시보철물로 바꾸어 주었다. 8주 기간 동안 지켜본 뒤 최종 보철물을 장착하여 6개월 경과 관찰 중이며 양호한 임상결과를 보였다.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1998년도 봄 학술발표회 논문집
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• pp.135-139
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• 1998

Poly(vinyl acetate) (PVAc) from which atactic poly(vinyl alcohol) (PVA) is derived, is always noncrystalline. This was attributed to the irregular steric arrangement of the acetyl groups in PVAc. However, the X-ray diffraction patterns of atactic PVA, a derivative of PVAc, were found to show distinct crystallinity, and to give an identity period of 2,52 ${\AA}$ along the fiber axis, despite the expectation of an irregular arrangement of the hydroxyl groups in atactic PVA, in the same manner as that of the acetyl groups in PVAc.(omitted)

• Journal of Advanced Marine Engineering and Technology
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• 제32권6호
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• pp.915-922
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• 2008

The gas separation technology using membrane is widely used to refine various gases in many industry fields and recently is being applying in $CO_2$ recovery technology. In the gas and chemical tanker. nitrogen generators for inerting, purging and padding are on board and most of them have membrane modules of hollow fiber type with long life and vibration resisting properties. Because a membrane module is a key component accounting for 50% of total manufacturing cost of nitrogen generator, adequate selection for it is an important problem. In this paper, the flow performance coefficient based on dimension and specification data of membrane module was relatively selected to compare nitrogen generating capacity of module and various performance tests about the selected PARKER ST6010 membrane module were conducted. As a result, the useful coefficient and basic data in selecting a membrane module were achieved.